Cyclohexane, 1,4-bis(ethoxymethyl)-

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to current guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

BASF SE, Experimental Toxicology and Ecology, 67056 Ludwigshafen, Germany

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(1r,4r)-1,4-bis(ethoxymethyl)cyclohexane; (1s,4s)-1,4-bis(ethoxymethyl)cyclohexane

EC Number:

700-868-7

Cas Number:

54889-63-3

Molecular formula:

C12 H24 O2

IUPAC Name:

(1r,4r)-1,4-bis(ethoxymethyl)cyclohexane; (1s,4s)-1,4-bis(ethoxymethyl)cyclohexane

Details on test material:

- Name of test material: 1,4-bis(ethoxymethyl)-Cyclohexane 97%
- Physical state/Appearance: Liquid / colorless, clear

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland GmbH, Sandhofer Weg 7, 97633 Sulzfeld, Germany
- Age at study initiation: male animals approx. 8 weeks, female animals approx. 11 weeks
- Weight at before exposure (day 0): mean = 227.4
- Fasting period before study: no fasting
- Housing: air conditioned rooms, Typ III polycarbonate cages, Wooden gnawing blocks as enrichment, single housing or up to 5 animals, Dust-free wooden bedding
- Diet: Kliba laboratory diet, mouse/rat maintenance “GLP”, 12 mm pellets ad libitum
- Water: Tap water ad libitum
- Acclimation period: at least 5 days before exposure

ENVIRONMENTAL CONDITIONS
- Temperature: 20-24 °C
- Humidity: 30-50 % for relative humidity
- Air changes: 15 per hour
- Photoperiod (dark/light): 12 hours / 12 hours

Experimental starting date: 22 Feb 2016
Day of last observation: 08 Mar 2016

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Nose-only inhalation system INA 20 (glass-steel construction, BASF SE
- Exposure chamber volume: approx. 55 L
- Method of holding animals in test chamber: restrained in glass tubes and their snouts projected into the inhalation system
- Source and rate of air: 1.5 m³/h
- Method of conditioning air: The central air conditioning system provides cold air of about 15°C. This cold air passes through an activated charcoal filter, is adjusted to room temperature of 20 to 24°C and passes through a second particle filter (H13 (HEPA) Camfil Farr, Germany).
- System of generating particulates/aerosols: The aerosol was produced by continuously pumping amounts of the test substance into the two-compnent atomizer. Equipement: Two-component atomizer Mod. 970 (stainless steel, Schlick), Continuous infusion pumps PHD Ultra (Harvard Apparatus,
Inc., Holliston, Massachusetts, U.S.A.)
- Method of particle size determination: Analysis by GC
- Treatment of exhaust air: The exhaust air was filtered and conducted into the exhaust air of the building (air flow 1.35 m³/h)
- Temperature, humidity, pressure in air chamber: 21.6 °C temperature, 17.4 (%) relative humidity, 1.5 bar atomizer pressure

TEST ATMOSPHERE
- Brief description of analytical method used: GC (System: Shimadzu 2010 with autosampler, FID, Dionex Chromeleon-Software (Dionex), or equivalent system; Column: Length: 30 m, Inner diameter: 0.25 mm, Film thickness: 0.25 µm; Stationary phase: Rtx-5 Amine, Restek or equivalent; Sample solution: Samples are diluted completely with isopropanol using appropriate volumetric flasks to obtain sample solutions with test substance concentrations that match the calibration range; Retention time for test substance: approx. 10 min)
- Samples taken from breathing zone: yes

TEST ATMOSPHERE
- Particle size distribution: Mass < 3 µm: 60.9 %
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 2.2 µm and 2.3 µm with GSD of 2.8

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

5.207 mg/L with 0.1 standard deviation

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of clinical observations: Clinical observations were recorded for each animal before exposure, separately several times during exposure (usually hourly) and after exposure. At least once daily on the preexposure day and during the post exposure observation period.
- Frequency of weighing: Individual body weights once during the acclimatization period, shortly before exposure (day 0) and at least on days 1, 3 and 7, and before the sacrifice of the animals at the end of the observation period.
- Necropsy of survivors performed: yes
- Other examinations performed: Mortality, Feed and Water

Statistics:

The binomial test was used for statistical evaluation.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.207 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occurred at the tested concentration.

Clinical signs:

other: Clinical signs of toxicity comprised of red encrusted nose, abdominal respiration indicating local irritation effect. Moreover, piloerection and substance contaminated fur. The effects were observed after exposure until the study day 1. No clinical signs

Body weight:

The mean body weights of the animals decreased on the first post exposure observation day but increased thereafter.

Gross pathology:

No gross pathological abnormalities were detected during the necropsy in the animals at the termination of the study.

Any other information on results incl. tables

Clinical observations

Table 1: Duration of signs

Test group 1 (5.207 mg/L)	Male animals	Female animals
Fur, substance contaminated	d0 - d1	d0 - d1
Nose, red encrusted	d0	d0
Respiration, abdominal	d0	d0 - d1
Piloerection	d0 - d1	d0 - d1

No abnormalities were detected in the animals during the post exposure observation period from study day 2 onwards.

 

Exposure conditions

Table 2: Exposure conditions

Supply air (m³/h)	Exhaust air (m³/h)	Test substance flow (mL/h)	Atomizer pressure (bar)	Temperature (°C)	Relative humidity (%)
1.5 ± 0.0	1.3 ± 0.0	23 ± 0.0	1.5 ± 0.0	21.6 ± 0.1	17.4 ± 0.8

 

Concentration measurements

Table 3: Analytical concentrations

Mean (mg/L)	Standard deviation	Nominal concentration (mg/L)
5.207	0.100	13.8

 

Particle size analysis

Table 4: Results

Sample	MMAD (µm)	Geometrical standard deviation
1	2.3	2.8
2	2.2	2.8

 

Statistical Evaluation

LC₅₀(both sexes combined):    > 5.207 mg/L (statistical significant to a level of 99 %)

LC₅₀(male rats):                       > 5.207 mg/L (statistical significant to a level of 95 %)

LC₅₀(female rats):                    > 5.207 mg/L (statistical significant to a level of 95 %)